In particular, parents should be aware of "community guns," which are hidden by gangs or criminal groups in public places and can be inadvertently found by children or teenagers.

"The idea behind community guns is to have one person not directly possess a firearm," Gramiccioni said.

The prosecutor said a child or teen who stumbles on a community gun might not intend to do harm, but could do so accidentally. He suggests parents and guardians have honest discussions with their kids about the dangers of firearms.

"Young people especially tend to forget how dangerous firearms can be," Gramiccioni said, reminding parents of how guns are sensationalized on television and in video games.

The prosecutor said it's a problem that affects cities as well as suburbs.